Sanding machine



' Feb.2,1943. y s 'DQ-LEE. l2,309,913.

SANDING MACHINE Filed oct. 12, 1940v Envenfor BB MVO? @um Patented Feb. 2, 1943 I Application October 12, 1940, Serial No. 360,933 ciaims. (C1. 51-181) This invention relates to portable Sanders of the type wherein the driving motor for the sanding' tool is built into the machine itself and the sanding tool is an abrading disc revolving about an axis 'at right angles to that of the motor shaft and is brought into working relation to the surface to be abraded by manipulating the machine as a unit bodily with respect to such surface.

Such -machine is standard in the trade and while satisfactory for performing some of the abrading operations commonly experienced on a sanding job is open to the objection that it cannot perform all of the abrading operations which the job may present.

This is due to the circumstance that the sanding t-oolis a thin flat disc and hence its abrading face can only be presented to the surface to be abraded in a plane which is generally parallel to such surface. This limits the possible use of the machine to surfaces which offer no obstruction to the manipulation of the disc in a lgelnerally parallel path thereover, and prohibits its use on surfaces which offer obstructions preventing the flat abrading face of the disc from completely contacting the same in all areas thereof.

The main object of my invention is to provide an attachment for a sander of this type which will increase the usefulness of the machine by overcoming the aforesaid objection.

In achieving this object, I construct the work tool as a relatively wide roll having both a peripheral working face and a planar Working face, so that by properly manipulating the machine either yWorking face may be presented to the surface to be abraded accordingly as the nature 'of such surface may require.

I have also devised a simple Iand enlcient form of mounting by means of which such work-roll may be quickly and easily mounted on the tool spindle of the machine in such position that it will clear the motor housing in any working'positionto which the machine may be manipulated.

Other advantages of my invention will appear as the description proceeds.

Fig. 1 is a t'opplan View of a sander of conventional type equipped with a work-tool in accordance with my invention.

Fig. 2 is a fragmentary side view thereof.

Fig. 3 is a perspective View of the work tool removed from the machine, the detachable and renewable abrading disc with which said work tool is normally equipped being removed for purposes of clarity of illustration.

Fig. 4 is a lperspective view of such renewable abrading disc.

Fig. 5 is a vertical section through the worktool and showing the same in mounted position upon the work spindle, and y Fig. 6 is a diagram illustrating two of the many possible uses of a machine equipped with my attachrnent.

The machine comprises the usual motor housing l0 for an electric motor (not shown). Extending axially from the housing IS at one end is the usual handle Il through which the feed' cable for the motor is entered. Extending axially from the opposite end of the housi-ng lll is the usual housing I2 for the reduction gearing (not shown) between the motor shaft and the tool spindle i3 which extends at right angles to the motor shaft.

The tool spindle I3 is reduced and externally threaded as at I4 (see Fig. 5). Detachably mounted upon the threaded extension I4 is an adaptor in the form of a bushing l5 having a hollow bore of a diameter to snugly receive said threaded extension. The bore is open at one end and closed at its other end and is internally threaded as at I6 to cooperate with the external threads of the extension l Il.

At its open end, the adaptor i5 is provided with an enlarged annular clamping ange il adapted to be brought into facial Contact with one face of the work tool. At its closed end, the adaptor i5 is reduced and externally threaded as at I8.

The work tool, indicated generally at i3, is in the form of a roll or wheel comprising an inner segmental core Eil-2G', of wood or the like, an intermediate split layer of felt or other resilient backing material 2| clamped to the periphery of said core, an an outer split layer of emery paper or other abrasive material clamped to the periphery of said backing layer f2l (see Figs. 3 and 5).

The core is lined with a bushing 23 which is flanged at one end as at 24. An adjustment screw 25 extends at right angles from said liner 23 and is anchored at its free end ,in one segment 20 of the segmental core. By adjustingv this screw, with a suitable tool inserted through the slot 20b (Fig. 3), the segment 20' may be moved sufliciently relative to the other segment 20 to which itis hinged as at 29a to permit the abrading layer 22 to be renewed when necessary. The tool may be any device which can be inserted through the slot 20h to engage with the exposed part-of the transverse slot 25a in the shank of the screw 25.

Detachably clamped against one face of the work-tool I9 is a renewable abradng disc 26 (Fig. 4). The vdisc 26 is centrally apertured to fit over the reduced threaded end I8 of the adapter I and is clamped in position by means of a clamping nut 21. As shown in Fig. 5, the bushing 23 terminates inwardly of the end of the roll and the bore through the wooden core members 20-20 flares outwardly at its outer end. Between these beveled surfaces T and the shoulder 24 may -be inserted a collar C. The nut 21 has a central hub portion to enter the aperture of the disc and said hub is internally threaded as at 28 to cooperate with the external threads IB. Surrounding the hub is an enlarged head 29 to bear against the outer face of the disc 26 adjacent the central aperture thereof and deiiect the same inwardly as shown in Fig. 5, the disc being scored as at 30 to permit such flexing. The inner face of the head 29 is tapered similarly to the portion T to hold the disc tightly in place on the end of the roll. The head 29 of the nut is apertured as at 3| for engagement by a Spanner in applying and removing the disc. The outer face of the head 29 when in disc-clamping position lies flush with theouter face of the disc on the end of the roll.

'In use, the flat abrading surface of the disc 26 is used for working upon a plane surface 32, as diagrammatically indicated in the showing at the right of Fig. 6. Should the surface to be abraded have a rabbet, as indicated at 33 in the showing at the left of Fig. 6, the machine is manipulated to present the peripheral abrading surface 22 of the work tool to such rabbet. And, if as frequently happensy it is desired simultaneously to abrade the surface 34 adjacent the rabbet, the abrading surface of the disc 26 is available. Thus the working capacity of the machine is substantially increased.

Although I have described my invention as an attachment for an existing sanding machine, it will be understood that the benefits thereof may be achieved in new machines without necessitating substantial redesign of the machine.

It will likewise be understood that my invention may be applied to abrading machines other than Sanders.

What I therefore claim and desire to secure by Letters Patent is:

1. An abrasive tool comprising a bushing for mounting on the work spindle of a motor, said bushing being bored longitudinally and having an open end to receive the spindle, an out-turned flange about said open end, the opposite end of said bushing being closed and reduced and provided with external screw threads, a second bushing terminating inwardly of said reduced portion and having an outturned flange providing a bearing shoulder, a roll core apertured to lie over said second bushing, said core outwardly of said shoulder flaring outwardly, a roll on said core, an abrasive covering removably clamped on the periphery of said roll, an abrasive faced disc apertured to encircle said reduced portion of the first bushing and to bear against said flaring core end and said shoulder, a clamping nut threaded to engage the threaded reduced end of said first bushing, said nut being tapered on its inner face to force said disc inwardly tightly against said concave core end and shoulder to hold said disc in place on the end of the roll, the outer surface of said nut being flush with the abrasive coated outer surface of said disc.

2. An abrasive tool comprising a bushing for mounting on the work spindle of a motor, said bushing being bored longitudinally and having an open end to receive said spindle, an outturned iiange about said open end of sufficient extent to clear said device from said motor, a second bushing over said iirst bushing and terminating inwardly of its outer end to provide a bearing shoulder, a core apertured to lie over said second bushing, a roll on said core having a Deripheral wall and an end wall, an abrasive covering for the peripheral wall of said roll, means removably clamping said covering against the peripheral wall of said roll, an abrasive-faced disc separate from said covering and adapted to encircle the outer end of said rst bushing and vbear against said shoulder, and means independnating inwardly of said reduced portion and hav-I ing an out-turned ange providing a bearing shoulder, a roll core apertured to lie over said second bushing, a roll on said core, an abrasive covering for the peripheral wall of said roll, means removably clamping said covering against the peripheral wall of said roll, an abrasive-faced disc separate from said covering and apertured to encircle said reduced portion of the first bushing and to bear against said shoulder, and means independent of said rst-named clamping means for forcing said disc inwardly tightly against said coreand shoulder to removably clamp said disc against the end wall of the roll.

4. An abrasive tool comprising a bushing, said bushing being hollow to receive the spindle of a motor, a roll on said bushing having a peripheral wall and an end wall, a covering of abrasive material for said peripheral wall, means removably Y clamping said covering against said peripheral wall, an abrasive disc separate from said covering, and means independent of said first-named clamping means 'for removably clamping said disc against the end wall of said roll.

5. The tool of claim 4, said bushing having an annular flange about its spindle receiving end providing an end bearing for said roll, said bushing extending through said roll from end to end :and being threaded on its outer end, and the clamping means for said disc being a fiat-headed flanged nut engageable with said threads to hold said disc against the end wall of the roll.

vSAMSON D. LEE. 

